Custom Device Research Articles

Midterm result of custom-made iliac branch device for common iliac aneurysm with and without abdominal aortic aneurysm.

Although commercial iliac branch devices offer a new and valid endovascular approach to treating iliac aneurysm and effectively preserve antegrade flow of the internal iliac artery, their use may not be suited for all types of challenging anatomy, especially isolated common iliac artery aneurysm. Our custom-made iliac bifurcation device has a unique design and excludes both combined and isolated iliac branch aneurysm. This study validated the efficacy and safety of the custom device by comparing clinical outcomes between groups receiving commercial and custom devices. Data of consecutive patients receiving iliac bifurcation device implantation for iliac aneurysm with or without concomitant endovascular repair for abdominal aortic aneurysm from January 2010 to May 2019 were reviewed. Iliac bifurcation device implantation with or without concomitant abdominal aortic aneurysm stent grafting was completed in 46 patients (commercial, n = 35; custom, n = 11). No significant differences were observed regarding postoperative complications, occlusion or endoleak. Comparisons of primary (80.8% vs 85.7%, P = 0.88) and secondary (86.5% vs 85.7%, P = 0.85) patency and freedom from reintervention (88.2% vs 100%, P = 0.33), all-cause mortality (78.6% vs 100%, P = 0.25) and aneurysm-related mortality (100% vs 100%, P = 1.00) also indicated no differences at a 5-year surveillance point. Furthermore, the iliac aneurysms of the groups displayed similar shrinkage 1 year after procedures. For iliac aneurysm, the novel custom-made iliac bifurcation device is an adaptable design not inferior to commercial devices with regard to postoperative complications, bridge occlusion, endoleak and short-term aneurysm remodelling. It provides an alternative for treatment, particularly when certain anatomic challenges are present. 2018-07-050BC, 2017-01-023ACF.

Brachial-ankle pulse wave velocity with a custom device

Background and objectivesThe brachial-ankle pulse wave velocity (baPWV) is one of the most widely used arterial stiffness variables for assessing vascular risk. The abiPWV is a device that calculates various PWVs and the blood pressure ankle-brachial index (ABI). The device can also determine baPWV. The aim of this study was to calculate the baPWV with abiPWV, validate it with a reference device (VaSera) and study its clinical usefulness. Patients and methodsWe studied 113 patients (mean age, 53 ± 12 years), 59 (52%) of whom were women, and 10 (8.8%) of whom had a previous cardiovascular event. The participants were classified according to cardiovascular risk factors (CRFs) into group I (none), group II (1 or 2 CRFs) and group III (3 or more CRFs). The patients with a previous cardiovascular event were included in group III. All participants had their baPWV measured with abiPWV and VaSera. ResultsThe baPWV correlation between the 2 devices was r = 0.93 (p < .001), and the percentage error calculated with the Bland-Altman analysis was 4.5%. The baPWV measured with abiPWV (in m/s) was as follows: group I, 10.5 ± 1.6; group II, 13.8 ± 2.9 (p < .001 when compared with group I); and group III, 14.1 ± 2.7 (p < .001 when compared with group I). There were no differences between groups II and III. The results with VaSera were comparable to those of abiPWV. ConclusionsMeasuring baPWV with the abiPWV is safe and has a similar clinical utility to that of VaSera. Incorporating this function into the options of abiPWV makes it a complete device for assessing arterial stiffness.

Torsional Resistance of WaveOne Gold and Reciproc Blue according to the Loading Methods

IntroductionThis study aimed to compare the torsional resistances and fracture modes of WaveOne Gold (Dentsply Sirona, Ballaigues, Switzerland) and Reciproc Blue (VDW, Munich, Germany) using the repetitive torsional loading (RTL) method and the conventional single-rotation (STL) method. MethodsA 3-mm file tip was fixed with a brass plate, and a torsional load was applied using a custom device. In the RTL method, the file was driven counterclockwise at 50 rpm until it achieved the preset torque of 0.5 Ncm; thereafter, it was returned to its original position. This recovery of the file to its original position was defined as 1 torsional loading cycle; the number of repetitive load cycles until fracture was counted. In the STL method, the files were rotated at a constant rate of 2 rpm in a counterclockwise direction until file fracture. The fragments fractured by the 2 methods were compared under a scanning electron microscope to examine the topographic features of the fractured surfaces and longitudinal aspects. ResultsWith the RTL method, Reciproc Blue showed a higher number of repetitive load cycles until fracture than WaveOne Gold (P < .05). With the STL method, Reciproc Blue also had a higher ultimate strength than WaveOne Gold (P < .05). Scanning electron microscopic findings of the fractured specimens from the 2 test methods showed different features of torsional failure. ConclusionsWithin the study limitations, both the RTL and STL methods conferred similar torsional resistance. Therefore, the clinically relevant RTL method with repetitive and reciprocation motion can be used for testing torsional resistance.

Abstract 334: Acute Effects of Nonexcitatory Electrical Stimulation During Systole in Human-induced Pluripotent Stem Cell Derived Cardiomyocytes

Cardiac contractility modulation (CCM) is a cardiac therapy whereby non-excitatory electrical simulations are delivered during the absolute refractory period of the cardiac cycle. CCM is indicated for patients with heart failure (Class III/IV) and reduced ejection fraction. We previously evaluated the effects of CCM and found isolated adult rabbit cardiomyocytes (rabbit-CMs) display a transient increase in calcium and contractility. In the present study, we sought to extend these results to human cardiomyocytes using human stem-cell cardiomyocytes (hiPSC-CMs). hiPSC-CMs were studied in both monolayer and isolated cells and results compared to that of rabbit-CMs. Contractility, calcium handling and electrophysiology was evaluated by image and fluorescence analysis. CCM was applied with a custom device covering a range of pulse parameters including standard clinical parameters (Figure 1). Pacing threshold was determined and stimulation performed at twice the diastolic capture threshold. Robust contractile response was observed at 16 V/cm, 70 mA for pacing and 28 V/cm, 120 mA for CCM. Under these conditions hiPSC-CMs and rabbit-CMs displayed increased contraction amplitude of 30 % (1.79 a.u., CCM vs 1.38 a.u., Control) and 22 % (3.67 a.u., CCM vs 3.00 a.u., Control) respectively and faster kinetics that subsided when the CCM signal was eliminated. This study provides a comprehensive characterization of the effects of CCM on hiPSC-CMs and rabbit-CMs in parallel under identical experimental conditions. These data provide the first study of CCM in hiPSC-CMs and demonstrates the potential utility of hiPSC-CMs to evaluate safety and effectiveness of cardiac medical devices.

A miniature mechanical testing device for testing hydrogel-based biomaterials in a confocal microscope.

Cardiac muscle cells are the fundamental building blocks of the heart, yet little is known about their mechanical properties in either healthy or diseased states. While many have explored unloaded myocyte behavior under a variety of interventions, methods for force measurements are limited due to cell fragility. Here, we present a custom device for manipulation and mechanical testing of hydrogels embedded with delicate cardiac muscle cells. Consisting of a custom disposable flexure, which is easily interchangeable, the device has the potential for high throughput testing of cell-gel constructs. Additionally, the mechanical testing device is the size of a microscope slide - appropriate for use in most microscopes, for simultaneous imaging of the sample. The mechanical properties of a gelatin-methacryloyl hydrogel sample were assessed, and 3D volumes of gel imaged using a confocal microscope. The Young's modulus of the gel was found to be 33kPa.Clinical Relevance- High-throughput testing provides the potential to gain insight into cardiac cell mechanics. Experimentation under the influence of a variety of pharmacological interventions could improve the rate at which treatments for cardiac disease are developed. Furthermore, methods may be extended to other embedded biological tissues.

Therapeutic hypothermia reduces cortical inflammation associated with utah array implants

Objective. Neuroprosthetics hold tremendous promise to restore function through brain-computer interfaced devices. However, clinical applications of implantable microelectrodes remain limited given the challenges of maintaining neuronal signals for extended periods of time and with multiple biological mechanisms negatively affecting electrode performance. Acute and chronic inflammation, oxidative stress, and blood brain barrier disruption contribute to inconsistent electrode performance. We hypothesized that therapeutic hypothermia (TH) applied at the microelectrode insertion site will positively modulate both inflammatory and apoptotic pathways, promoting neuroprotection and improved performance in the long-term. Approach. A custom device and thermoelectric system were designed to deliver controlled TH locally to the cortical implant site at the time of microelectrode array insertion and immediately following surgery. The TH paradigm was derived from in vivo cortical temperature measurements and finite element modeling of temperature distribution profiles in the cortex. Male Sprague-Dawley rats were implanted with non-functional Utah microelectrodes arrays (UMEA) consisting of 4 × 4 grid of 1.5 mm long parylene-coated silicon shanks. In one group, TH was applied to the implant site for two hours following the UMEA implantation, while the other group was implanted under normothermic conditions without treatment. At 48 h, 72 h, 7 d and 14 d post-implantation, mRNA expression levels for genes associated with inflammation and apoptosis were compared between normothermic and hypothermia-treated groups. Main results. The custom system delivered controlled TH to the cortical implant site and the numerical models confirmed that the temperature decrease was confined locally. Furthermore, a one-time application of TH post UMEA insertion significantly reduced the acute inflammatory response with a reduction in the expression of inflammatory regulating cytokines and chemokines. Significance. This work provides evidence that acutely applied hypothermia is effective in significantly reducing acute inflammation post intracortical electrode implantation.

Pitching shoulder passive flexibility: torque-angle analysis for external rotation and internal rotation

ABSTRACT In this study, a custom device was developed to analyse the pitching shoulder’s external rotation (ER) and internal rotation (IR) passive flexibility. We analysed three novel measures: the resistance onset angle (ROA = angle where the shoulder begins stretching), rotational stiffness, and torque at the end range of motion (ROM). The purpose was to conduct a bilateral analysis to determine if there are significant differences between the throwing and non-throwing shoulder. Participants were 30 upper level pitchers (13 division I, 17 minor league). During testing, pitchers laid supine on a treatment table and the arm was secured to a rotational wheel with the shoulder abducted 90° and elbow flexed 90°. Dependent t-tests revealed significant (p < 0.01) and relatively extreme bilateral differences for all three variables. The throwing shoulder had: increased ER ROA (9°), decreased IR ROA (5.3°), increased ER stiffness (17%), increased IR stiffness (34%), increased ER torque (21%), and increased IR torque (30%). Secondary correlation analysis was completed to determine if the torque-angle variables were good predictors of the end ROM. Stiffness correlations were weak for ER (r = 0.35, p = 0.048) and IR (r = 0.42, p = 0.017) but ROA correlations were strong for ER (r = 0.85, p < 0.001) and IR (r = 0.86, p < 0.001).

Roar Aboard: Protecting Service Members' Ears on Aircraft Carriers

Roar Aboard: Protecting Service Members' Ears on Aircraft Carriers

AAA 19. Midterm Results of Parallel Grafts in Patients With Pararenal and Type IV Thoracoabdominal Aortic Aneurysms Unsuitable for Fenestrated or Branched Endografts

The objective of this study was to evaluate the midterm outcomes of parallel grafts (PGs) in patients presenting with pararenal or type IV thoracoabdominal aortic aneurysms unsuitable for off-the-shelf or custom-made fenestrated or branched endografts. Between February 2011 and July 2019, there were 41 consecutive patients presenting with pararenal or type IV thoracoabdominal aortic aneurysms who were treated by implantation of PGs. Reasons for use of PGs were the following: patients judged unfit for open surgery; urgent or emergent procedures in which off-the-shelf graft was not applicable; and elective patients refused for manufacture of custom device because of anatomy. Different commercially available endografts and covered balloon or self-expandable stents were used. Outcomes included intraoperative technical success and early (30-day) and midterm all-cause mortality and morbidity as well as freedom from reintervention, endoleaks, and occlusions of PGs. Technical success was defined as a procedure completed as intended, without secondary interventions within 30 days. Forty-one patients were included (mean age, 76.3 ± 7.1 years; 34 male). Mean aortic aneurysm diameter was 67.2 ± 18.6 mm. Twenty-three patients were treated electively; the remaining patients were treated in emergency. Previous infrarenal aneurysm repair was reported in 11 patients (26.8%). Ninety-two target aortic branches (TABs) were treated (2.2/patient). Technical success was obtained in all patients. At 30 days, mortality was 7.4%, accounting for three emergently treated patients (two aortic infections and one rupture), and TAB occlusion rate was 2.1% (2/92). One patient required an additional embolization procedure because of a persistent gutter endoleak. At a mean follow-up of 29 ± 7 (2-96) months, freedom from mortality was 89.5%; four more patients died (one new infection, one aneurysm rupture, and two myocardial infarctions). Rate of TAB new occlusion was 1.1% (1/92). Reintervention was performed in four patients, in three for endoleaks and in one for iliac limb occlusion. During the entire study period, cumulative TAB occlusion rate was 3.2%, all renal branches. Aneurysm sac shrinkage was observed in 59.5% of patients, with a mean aneurysm diameter reduction 3.8 ± 2.1 mm. The technique of PGs seems to represent a reasonable option in patients at high risk for open surgery who are not able to be treated by fenestrated or branched endografts. Despite high clinical and anatomic risk of treated patients, TAB patency remains high at midterm follow-up.

Abstract 902: Leveraging Natural Cardiomyocyte Variability to Investigate Downregulation of β-1 Adrenoceptors Following Dobutamine Treatment

In heart failure, the most consistent effect on the myocardial beta-adrenergic pathway is a downregulation of β-1 adrenoceptors (β1AR). This loss of receptors impairs the ability of the heart to respond to increases in cardiac demand, and can lead to decreased myocyte function even at rest. As a model of the process that leads to downregulation of β1AR, we measured intracellular Ca 2+ transients and unloaded sarcomere shortening in electrically stimulated isolated adult rat cardiomyocytes undergoing 30 minutes of exposure to 40 nM dobutamine. These experiments were facilitated by a custom device containing micro-patterned wells that orient and immobilize the cardiomyocytes, allowing for rapid and consistent measurements over an extended time period. After functional measurements, cells are picked up individually with a computerized micro-aspirator and subjected to single-cell RT-qPCR to quantify abundance of transcripts of interest. In this way, the physiological responses of individual cells to β1AR stimulus can be correlated to gene expression levels. We found a surprising diversity in the single-cell responses to dobutamine exposure. Although average cardiomyocyte contractility increased significantly, several apparently healthy cells registered no change or even a decrease in sarcomere shortening in the presence of dobutamine. Gene expression was quantified in cardiomyocytes representing a spectrum of sensitivities to dobutamine (n = 7). The transcript for β1AR was significantly downregulated in all cells after 30 minutes, indicating consistent adaptation to chronic stimulus. However, abundance of the gene encoding PKA was negatively correlated with dobutamine-triggered augmentation of Ca 2+ release (p-value: 0.0201). In other words, PKA expression was reduced in cells that experienced potent increases in Ca 2+ release after dobutamine treatment. These data suggest the presence of gene regulatory circuits that modulate individual components of the β1AR pathway independent of overall β1AR abundance. These circuits may be critical to restoring β1AR sensitivity in the failing heart.

How much space do drivers provide when passing cyclists? Understanding the impact of motor vehicle and infrastructure characteristics on passing distance

Background: Understanding factors that influence the distance that drivers provide when passing cyclists is critical to reducing subjective risk and improving cycling participation. This study aimed to quantify passing distance and assess the impact of motor vehicle and road infrastructure characteristics on passing distance.Methods: An on-road observational study was conducted in Victoria, Australia. Participants had a custom device installed on their bicycle and rode as per their usual cycling for one to two weeks. A hierarchical linear model was used to investigate the relationship between motor vehicle and infrastructure characteristics (location, presence of on-road marked bicycle lane and the presence of parked cars on the kerbside) and passing distance (defined as the lateral distance between the end of the bicycle handlebars and the passing motor vehicle).Results: Sixty cyclists recorded 18,527 passing events over 422 trips. The median passing distance was 173 cm (Q1: 137 cm, Q3: 224 cm) and 1085 (5.9%) passing events were less than 100 cm. Relative to sedans, 4WDs had a reduced mean passing distance of 15 cm (Q1: 12 cm, Q3: 17 cm) and buses had a reduced mean passing distance of 28 cm (Q1: 16 cm, Q3: 40 cm). Relative to passing events that occurred on roads without a marked bicycle lane and without parked cars, passing events on roads with a bike lane with no parked cars had a reduced mean passing distance of 27 cm (Q1: 25 cm, Q3: 29 cm), and passing events on roads with a bike lane and parked cars had a mean lower passing distance of 40 cm (Q1: 37 cm, Q3: 43 cm).Conclusions: One in every 17 passing events was a close (<100 cm) passing event. We identified that on-road bicycle lanes and parked cars reduced passing distance. These data can be used to inform the selection and design of cycling-related infrastructure and road use with the aim of improving safety for cyclists.

Mechanical Properties of Various Glide Path Preparation Nickel-titanium Rotary Instruments

IntroductionThe aim of this study was to compare the cyclic fatigue, torsional resistance, and bending stiffness of single-file glide path preparation nickel-titanium instruments. MethodsProGlider (#16/progressive taper; Dentsply Sirona, Ballaigues, Switzerland), One G (#14/.03; Micro-Mega, Besancon, France), and EdgeGlidePath (#16/progressive taper; Edge Endo, Albuquerque, NM) were tested. For the bending stiffness test, the instrument was bent to a 45° angle along the main axis while 3 mm of the tip was secured. Cyclic fatigue resistance was measured during pecking movement, whereas the file was rotated within a reproducible simulated canal with a 3-mm radius and a 90° angle of curvature. The ultimate torsional strength and toughness were evaluated using a custom device. While tightly holding the end of the file at 3 mm, a rotational load of 2 rpm speed was applied until fracture. The results were analyzed using 1-way analysis of variance and Tukey post hoc comparison. A microscopic inspection was performed on the surface of a separate instrument using a scanning electron microscope. ResultsEdgeGlidePath showed superior cyclic fatigue resistance compared with the other systems. One G showed higher maximum torsional strength than the others. One G showed the largest distortion angle and the highest toughness followed by EdgeGlidePath and ProGlider (P < .05). One G also showed larger bending stiffness than the others, whereas EdgeGlidePath showed a larger residual angle than the others (P < .05). ConclusionsConventional wire showed higher toughness and torsional resistance than M-Wire and heat-treated nickel-titanium instruments. However, heat-treated wire showed higher cyclic resistance than conventional wire and M-Wire.

Snap-On User-Space Manager for Dynamically Reconfigurable System-on-Chips

Due to increased embedded processing requirements, modern SoCs are becoming heterogeneous computing platforms by combining traditional processing units with custom reconfigurable hardware accelerators (HAs) on an FPGA fabric. However, efficiently managing such HAs in an embedded Linux environment involves handling Linux kernel source code and creating custom device drivers specific to a target platform, therefore negatively impacting development costs, portability and time-to-market. To address this issue, we present LEOSoC, a snap-on user-space manager for dynamically reconfigurable SoCs. Using LEOSoC does not require any specific version of the Linux kernel, nor to rebuild a custom driver for each new kernel release. LEOSoC consists of a base hardware system and a software layer which run on SoCs from various vendors. The system identifies the SoC on which it is running and auto-adapts its communication channels to the HAs accordingly. Furthermore, LEOSoC allows applications to partially or completely change the structure of the HAs at runtime without rebooting the system by leveraging the underlying SoC support for dynamic full/partial FPGA reconfiguration. The system has been tested on multiple commercial off the shelf (COTS) boards from different vendors, each one running different versions of Linux, therefore proving the real portability and usability of LEOSoC in a custom industrial design. Finally, we use a cloud detection algorithm for multispectral image processing as a showcase for LEOSoC's capabilities and performance.

Validation of Instantaneous Respiratory Rate Using Reflectance PPG from Different Body Positions.

Respiratory rate (RR) is a key parameter used in healthcare for monitoring and predicting patient deterioration. However, continuous and automatic estimation of this parameter from wearable sensors is still a challenging task. Various methods have been proposed to estimate RR from wearable sensors using windowed segments of the data; e.g., often using a minimum of 32 s. Little research has been reported in the literature concerning the instantaneous detection of respiratory rate from such sources. In this paper, we develop and evaluate a method to estimate instantaneous respiratory rate (IRR) from body-worn reflectance photoplethysmography (PPG) sensors. The proposed method relies on a nonlinear time-frequency representation, termed the wavelet synchrosqueezed transform (WSST). We apply the latter to derived modulations of the PPG that arise from the act of breathing.We validate the proposed algorithm using (i) a custom device with a PPG probe placed on various body positions and (ii) a commercial wrist-worn device (WaveletHealth Inc., Mountain View, CA, USA). Comparator reference data were obtained via a thermocouple placed under the nostrils, providing ground-truth information concerning respiration cycles. Tracking instantaneous frequencies was performed in the joint time-frequency spectrum of the (4 Hz re-sampled) respiratory-induced modulation using the WSST, from data obtained from 10 healthy subjects. The estimated instantaneous respiratory rates have shown to be highly correlated with breath-by-breath variations derived from the reference signals. The proposed method produced more accurate results compared to averaged RR obtained using 32 s windows investigated with overlap between successive windows of (i) zero and (ii) 28 s. For a set of five healthy subjects, the averaged similarity between reference RR and instantaneous RR, given by the longest common subsequence (LCSS) algorithm, was calculated as 0.69; this compares with averaged similarity of 0.49 using 32 s windows with 28 s overlap between successive windows. The results provide insight into estimation of IRR and show that upper body positions produced PPG signals from which a better respiration signal was extracted than for other body locations.

Auracle

In this paper, we propose Auracle, a wearable earpiece that can automatically recognize eating behavior. More specifically, in free-living conditions, we can recognize when and for how long a person is eating. Using an off-the-shelf contact microphone placed behind the ear, Auracle captures the sound of a person chewing as it passes through the bone and tissue of the head. This audio data is then processed by a custom analog/digital circuit board. To ensure reliable (yet comfortable) contact between microphone and skin, all hardware components are incorporated into a 3D-printed behind-the-head framework. We collected field data with 14 participants for 32 hours in free-living conditions and additional eating data with 10 participants for 2 hours in a laboratory setting. We achieved accuracy exceeding 92.8% and F1 score exceeding 77.5% for eating detection. Moreover, Auracle successfully detected 20-24 eating episodes (depending on the metrics) out of 26 in free-living conditions. We demonstrate that our custom device could sense, process, and classify audio data in real time. Additionally, we estimate Auracle can last 28.1 hours with a 110 mAh battery while communicating its observations of eating behavior to a smartphone over Bluetooth.

Measurement Methodology for Accurate Modeling of SiC MOSFET Switching Behavior Over Wide Voltage and Current Ranges

This paper presents two novel measurement methods to characterize silicon carbide (SiC) MOSFET devices. The resulting data are utilized to significantly improve the extraction of a custom device model that can now accurately reproduce device switching behavior. First, we consider the $I_{\text{d}}- V_{\text{ds}}$ output characteristics of power devices such as SiC transistors. These are typically measured using traditional curve tracers, but the characterization of the high-voltage and high-current (HVHC) region is very challenging because of device power compliance and self-heating. In this paper, we introduce a measurement technique that overcomes self-heating and derives the HVHC region from switching waveforms. The switching transient characteristics of devices are used to determine drain current $(I_{\text{d}})$ as a function of drain–source voltage $(V_{\text{ds}})$ in the HVHC range. Second, we consider another challenging characterization area: measurement of nonlinear capacitances when device is turned on. These capacitance characteristics of on-state devices are important for correcting disagreements between simulations and measurements in turn-off switching transient waveforms and cannot be measured using a conventional capacitance-voltage meter. We introduce S-parameter measurements as an effective method to obtain the capacitance characteristics of both off-state devices and on-state devices. These novel measurement techniques have been applied to the modeling of a SiC device. The extracted device model, a modified version of the popular Angelov−GaN high-electron-mobility transistor model, shows significant improvement in terms of the accuracy of switching waveforms of devices over a wide range of operating conditions.

Safe pseudoelastic limit range under torsional loading with Reciproc Blue.

To determine the distortional angle and torsional load at the pseudoelastic limit of Reciproc Blue instruments and to verify the safety of using pre-set dedicated motors designed for use with the original Reciproc instruments. Two torsional conditions of Reciproc R25 and Reciproc Blue R25 were tested using a custom device. The first condition fixed the file tips at 3mm and repetitively rotated them, with gradually increasing angles, from 10° to 270°, and the resulting torque was recorded (n=15). The second test involved a single continuous rotation until fracture (n=15). The pseudoelastic limits of the instruments were determined from their torque-rotation curves. For statistical analysis, two-way analysis of variance and t-tests were used, at a 95% significance level. Tested specimens were examined using field-emission scanning electron microscopy (FE-SEM). The angle at the pseudoelastic limit was significantly greater for Reciproc Blue than Reciproc, regardless of test mode (P<0.05). When torsional loading was repeated, using gradually increasing rotational angles, the torsional resistance was significantly lower than for a single rotation (P<0.05). However, under all test conditions, the pseudoelastic limit was below the pre-set 170° of the dedicated reciprocating motor. FE-SEM evaluation of the lateral aspects of the instruments revealed numerous longitudinal microcracks running along their long axis. For Reciproc Blue groups, the file shaft machining grooves were distorted after repetitive and continuous torsional tests. The 170° pre-set angle of the dedicated endodontic motors for the Reciproc system was safe for Reciproc Blue in single or time-restricted use.

End-to-End Sample Tracking in the Laboratory Using a Custom Internet of Things Device.

We describe a custom Internet of Things (IoT) device used for tracking barcoded containers end to end in a high-throughput analysis and purification laboratory. Our IoT device fills an important gap that previously prevented us from fully tracking barcoded sample containers through manual steps in a multistep workflow, such as when samples are "parked" for temporary storage, or when using instrumentation not otherwise equipped with barcode scanners, a common occurrence found with specific centrifugal evaporation instruments. The custom device reads container barcodes and sends a small amount of data to our back-end data systems. Once data have been received and processed, users are alerted to any system responses via aural and visual feedback. Components of the IoT system include a low-cost headless IoT computer, a barcode reader, and a multicolor LED strip. We believe that the model for our device will facilitate simple and rapid deployment of IoT to the broader laboratory community. All source code and device configurations will be released into the public domain and made freely available.

Ranges of modifications in step width and foot progression angle for everyday walking

Gait retraining through instructions to modify step width (SW) and foot progression angle (FPA) is quickly gaining in interest for the rehabilitation of a range of pathologies. Diverse systems have been proposed to guide the patients modifying these variables, but their uses are limited by the paucity of data regarding individuals’ willingness to walk with these modifications. This study aimed at characterizing the range of SW and FPA modifications that individuals would consider walking with. Ten healthy subjects (6 males; 25 ± 6 years old; 22 ± 2 kg/m 2 ) performed 10 m long walking trials with various amplitudes of SW and FPA modifications ( Table 1 ) in a gait lab equipped with a motion capture system (Vicon, UK) linked to a custom device displaying footprint instructions on the ground. After each trial, the participants indicated whether they “could” or “were not willing or able to” walk with the proposed modification every day. Ninety percent or more of the participants indicated that they could walk every day with SW modifications between −0.10 m and +0.16 m ( Table 1 ). Less than 50% would however consider larger amplitudes of SW modifications. Concerning FPA, 90% or more reported that they could walk every day with modifications in the range −10°C to +10°. Fifty to 90% would either consider larger FPA increases (up to 20°), whereas less than 50% would consider larger decreases. This study showed that healthy subjects would be willing modifying SW and FPA. It further provided first modification ranges, between −0.10 m and +0.16 m and between −10° and +10° that a vast majority would consider for everyday walking. This study therefore confirmed the potential of SW- and FPA-based gait retraining and provided important information for the design of future rehabilitation protocols.

An open-source realtime computational platform (short WIP paper)

Systems neuroscience studies involving in-vivo models often require realtime data processing. In these studies, many events must be monitored and processed quickly, including behavior of the subject (e.g., movement of a limb) or features of neural data (e.g., a neuron transmitting an action potential). Unfortunately, most realtime platforms are proprietary, require specific architectures, or are limited to low-level programming languages. Here we present a hardware-independent, open-source realtime computation platform that supports high-level programming. The resulting platform, LiCoRICE, can process on order 10e10 bits/sec of network data at 1 ms ticks with 18.2 µs jitter. It connects to various inputs and outputs (e.g., DIO, Ethernet, database logging, and analog line in/out) and minimizes reliance on custom device drivers by leveraging peripheral support via the Linux kernel. Its modular architecture supports model-based design for rapid prototyping with C and Python/Cython and can perform numerical operations via BLAS/LAPACK-optimized NumPy that is statically compiled via Numba’s pycc. LiCoRICE is not only suitable for systems neuroscience research, but also for applications requiring closed-loop realtime data processing from robotics and control systems to interactive applications and quantitative financial trading.